WTF?! Where'd the rest of the message go?! Anyway, let's try again.
Textures are patterns, designs, etc...that you use to use to give something texture >.< They g on top of whatever image you're working with. Just play with the blending options and opacity until you find something that looks good.
IE: The washed out look of my avatar is from using textures.
I get the textures used for avatars here.

@KCHuang:

Textures are patterns designs etc...that you use to use to give something texture >.

@KCHuang:

Really, backgrounds are like the easiest thing to make. Just start with a blank canvas. You can either use the paint bucket or gradients to fill it in, and then just pile on brushes (they stay on the same layer as the color used) and textures on top of it. It's easy to let it get it out of hand, so as you go, just stop for a second and decide if what's on it looks good and you really want it there. Try it out, and I demand to see the result!